Formspring, a once-buzzy site that counted more than 28 million users for its ask-me-a-question service, was the Snapchat of its day—an Internet service popular with teens and misunderstood by adults, and well-funded by eager venture capitalists.

Formspring had an incredibly rapid rise, hitting a million users in its first 45 days and growing to 32 employees. It faced a wave of controversy as teens exploited the anonymity of its question-asking service to bully others.